正则表达式在找到文本并且缺少其他文本时进行搜索

Question

我有以下文字:

application ONE {
    protocol tcp;
    destination-port 50;
}
application TWO {
    protocol udp;
    destination-port 51;
    inactivity-timeout 800;
}
application THREE {
    protocol udp;
    destination-port 500;
}

我需要搜索每个 application , 当 protocol是 udp , 如果 inactivity-timeout不同于 1800(应用程序二)或 protocol是 udp并且没有定义不活动(应用程序三)。
我用正则表达式解决了第一种情况:

(?s)(?=protocol udp).*(inactivity-timeout (?!1800))

但我还没有找到获得第二个的方法。

有什么建议么？

Answer 1

你用 Java 标记了这个，所以我给你一个 Java 解决方案，虽然我不确定你的帖子是否是你想要的。

就个人而言，我会将问题分为两部分。首先，提取应用程序，其次，检查应用程序是否符合要求。这是我的尝试。

public class ApplicationReadOut {

    public static String EXAMLPLE = "application ONE {\r\n"
        +"    protocol tcp;\r\n"
        +"    destination-port 50;\r\n"
        +"}\r\n"
        +"application TWO {\r\n"
        +"    protocol udp;\r\n"
        +"    destination-port 51;\r\n"
        +"    inactivity-timeout 800;\r\n"
        +"}\r\n"
        +"application THREE {\r\n"
        +"    protocol udp;\r\n"
        +"    destination-port 500;\r\n"
        +"}\r\n";

    public boolean checkApplication(String app) {
        String[] lines = app.split("\r\n");
        boolean udp = false;
        boolean timeoutDiffers = true;
        boolean timeoutMentioned = false;
        for (String line : lines) {
            if (line.trim().equals("protocol udp;"))
                udp = true;
            if (line.trim().equals("inactivity-timeout 1800;"))
                timeoutDiffers = false;
            if (line.trim().startsWith("inactivity-timeout "))
                timeoutMentioned = true;
        }
        return udp & (timeoutDiffers | !timeoutMentioned);
    }

    public String[] extractApplications(String text) {
        String[] applications = text.split("}(\r*\n*)*"); 
        // the \r\n thing is to ignore blank lines in between applications
        ArrayList<String> goodApps = new ArrayList<String>(applications.length);
        for (int i = 0; i < applications.length; i++) {
            applications[i] += "}"; // this was removed by split
            if (checkApplication(applications[i]))
                goodApps.add(applications[i]);
        }
        return goodApps.toArray(new String[0]);
    }


    public static void main(String[] args) {
        ApplicationReadOut aro = new ApplicationReadOut();
        System.out.println(Arrays.toString(aro.extractApplications(EXAMLPLE)));
    }

}

我希望这很有用，您可以修改它以满足您的需要:-)